Hotfix for external trigger

This release will address pr #132 #133

• rate issue with external triggering
• fixing queue in /camera msg name field

External trigger, gain, ROI, Spinnaker 2.2.x compatibility

The version includes the following major changes:

1. Add external triggering
2. ROI settings for images
3. Adding gain settings to code
4. Number of little improvements and bug fixes.

hot-fix based on pr #36

hot-fix based on pr #36 fixes

1. the node shutdown, when intrinsics are not provided. now publishes zeros in intrinsics
2. if more cameras are plugged into host machine than cam_ids specified in params, the node doesn't die.

Nodelets, image transport, dynamic reconfigure

Major changes in this release:

• Nodelets implemented for faster access to code using the images
• Image transport now being used instead of standard transport
• Dynamic reconfigure for Exposure and target grey values

uas_version_before_merge

uas_v1.0

added respawn